Sample dilution device-disc diluter

ABSTRACT

A device for obtaining a representative sample of a gaseous emission stream and diluting sample with clean air so that the resulting stream can be subsequently analyzed.

United States Patent [191 Homolya et al.

[ Apr. 16, 1974 SAMPLE DILUTION DEVICE-DISC DHLUTER Inventors:

Assignee:

Filed:

Appl. No.:

US. Cl..... Int. Cl.

James B. Homolya, Cary; Robert James Griffin, Durham, both of NC.

The United States of America as represented by the Administrator of the Environmental Protection Agency, Washington, DC.

Nov. 15, 1972 73/42l.5 R, 73/422 TC GOln 1/22 Field of Search. 73/42l.5 R, 421.5 A, 422 GC,

[56] References Cited UNITED STATES PATENTS 3,699,814 10/1972 Kaufman 73/42l.5 R 3,080,759 3/1963 McQuaid.... 73/422 GC 3,368,385 2/1968 Harvey 1. 73/422 GC 3,266,321 8/1966 Fenske 73/422 Primary Examiner-S. Clement Swisher [57] 1 ABSTRACT A device for obtaining a representative sample of a gaseous emission stream and diluting sample with clean air so that the resulting stream can be subsequently analyzed.

9 Claims, 8 Drawing Figures PATENTEU R 1 m Y SHEEI 2 BF 2 VIII/1111110 SAMPLE DILUTION DEVICE-DISC DILUTER This invention relates to a method and means for obtaining a representative sample of a gaseous emission stream and diluting the sample with clean air, whereby the resulting stream will be free from particulates and large amounts of moisture so that the resulting stream can be subsequently analyzed by a suitable conventional apparatus.

The primary object of the present invention is to provide a device that is to be used for an in-stack dilution system, and wherein there is provided a rotating perforated disc that is adapted to be located or positioned in a stack gas atmosphere.

A further object of the present invention is to provide a disc diluter that can be used in pollution measure ment, although it is not limited to such use, and wherein the disc diluter can be used as any application that requires a single step dilution.

Still another object is to provide a sample dilution device-disc diluter that is economical to manufacture and efficient in operation and which is rugged in structure and fool-proof in use.

These and other objects of the invention will become apparent from a reading of the following specification The numeral 32 indicates a line or tube that is adapted to be connected to a conventional gas analy zer, and the line 32 has a gas sample to be analyzed flowing therethrough. An inlet line or tube 33 is arranged as shown in the drawings, and the tubing 33 is adapted to be connected to a suitable source of clean air, there being a needle valve 34 and meter 35 in the line 33. Portions of the lines 32 and 33 are adapted to extend through the pipe 22, as shown in the drawings.

The numeral 36 indicates a rectangular fitting or bracket that may be secured as by welding to the drive shaft 23, and fitting 36 is snugly received in a recess 37 in the rotary disc 27 so that as the shaft 23 is driven by the motor 17 the disc 27 will be rotated between the discs 25 and 26.

and claims, together with the accompanying drawings, 1

wherein like parts are referred to and indicated by like reference characters, and wherein:

FIG. 1 is a diagrammatic view of the sample dilution device of the present invention;

FIG. 2 is an enlarged fragmentary side elevational view of the dilution device of 'FIG. 1; g

FIG. 3 is an end elevation view partly broken away taken on the line 3-3 of FIG. 2;

FIG. 4 is a vertical sectional view, with parts broken away for purposes of clarity, taken on the line 4--4 of FIG. 2;

FIG. 5 is an enlarged horizontal sectional view, taken on the line 55 of FIG.-4;

FIG. 6 is an enlarged vertical sectional view, taken on the line 66 of FIG. 4;

FIG. 7 is a fragmentary vertical view, partly in section, taken on the line 77 of FIG. 6; and

FIG. 8 is an enlarged horizontal sectional view, taken on the line 88 of FIG. 4.

Referring in detail to the drawings, there is illustrated a sample dilution disc diluter device that is adapted to be mounted in a conventional stack or duct 21 that has an opening 19 therein for the projection therethrough of a pipe 22. The pipe 22 may be secured as by welding to a plate 18 that is removably mounted adjacent the openings 19 in the stack 21. The numeral 23 indicates a drive shaft that extends through the pipe 22, and an end portion 24 of the drive shaft 23 is connected to a motor 17, FIG. 1.

The numerals 25 and 26 indicate first and second spaced parallel circular discs that are stationary, and the numeral 27 indicates a third disc that is mounted for rotation between the discs 25 and 26, the disc 27 being of less diameter than the disc 25 and 26. As shown in FIG. 6, the discs 25 and 26 have registering openings or apertures 28 therein and securing elements such as bolts 29 extending through the openings 28 and have coil springs 30 mounted thereon for a purpose to be later described, there being nuts or fasteners 31 for maintaining the parts in their proper assembled position.

The rotary disc 27 has a plurality of spaced apart openings or ports 38 therein. The stationary disc 25 and 26 have elongated apertures or openings 39 and 40 therein, as shown in FIGS. 3, 4, 5 and 6.

The numeral 41 indicates a housing that may be secured to the disc 26 in any suitable manner as, for example, by means of securing elements 16, and the housing 41 has passageways 42 and 43 therein, FIG. 8. The disc 26 has a port 44 therein, as shown in FIG. 6. Chamber 15 is arranged in housing 41 and connects passageway 42 to port 44. The numeral 14 indicates a port or nozzle in housing 41 that connects passageway 43 to port 44, as shown in FIG. 8.

From the foregoing, it will be seen that there has been provided a sample dilution device and disc diluter, and in use with the parts arranged as shown in the drawings, the pipe 22 is adapted to be extended through the openings 19 in the wall of the stack 21, and the unit 20 is arranged, as shown in FIG. 1. The line or tubing 33 can be connected to a suitable source of clean air, and the line or tubing 32 can be connected to conventional gas analyzers. When it is desired to analyze the gas flowing through the stack 21, and with the parts arranged as shown in FIG. 1, the motor 17 will rotate or drive the shaft 23 due to the provision of the coupling 24. The fitting 36 is suitably secured to the inner end of the shaft 23, and the fitting 36 is snugly received in the recess 37 of the rotary perforated disc 27, so that when the shaft 23 is driven by the motor 17, the perforated disc 27 will rotate between the pair of sta tionary discs 25 and 26. By loosening or tightening the nuts 31, the pressure exerted by the springs 30 can be varied as desired so that the disc 27 can rotate in proper manner.

As the disc 27 rotates, the perforations or openings 38 in the disc 27 will move into and out of alignment with the registry of the openings 39 and 40, whereby the gas to be analyzed will be picked up by the pockets or openings 38 through the openings 39 and 40. As the disc 27 continues to rotate, this gas sample will be carried around until the pockets 38 are sucessively in alignment with the passageways 42 and 43 in the housing 41 via the port 44 and passageways l5 and 14, and at this time a quantity of clean air can enter the system through the passageways 43 and 14 so as to dilute the sample with clean air so that the sample as diluted with clean air can be discharged through the passageways 15 and 42 to the analyzers via tube 32.

The parts can be made of any suitable material and in different shapes and sizes and as desired or required.

The present invention is used to obtain a representative sample of a gaseous emission stream and dilute the sample with clean air, and the resulting streams, substantially free from particulates and large amounts of moisture, can be fed to any suitable commercially available analyzers. Thus, the present invention will dilute any gaseous stream, and with this device peripheral hardware and/or equipment is minimized. The dilution ratio attainable by the device covers a wide range. Also, the device eliminates problems due to moisture condensation and particulate entrainment. The physical configuration of the device can be readily modified to meet existing needs or requirements.

The device is an in-staek dilution system that uses or is based on a rotating perforated disc such as the disc 27 to be located in a stack gas atmosphere. The disc 27 is held in place between two stationary discs 25 and 26. The stationary discs 25 and 26 each have an opening 39 and 40 to permit a gas exchange to take place between the perforated openings 38 in the disc 27 and the stack gas atmosphere. As the gas exchange takes place, the moving disc 27 rotates to permit the perforations 38 containing stack gas to come in contact with the small enclosed chamber 41 on the stationary disc 26. A metered stream of air diluent is passed through the passageway 43 from the line 33 and through the fine nozzle 14 located in the chamber 41, FIG. 8, so as to create a jet of air that strikes the perforations 38 in the rotating disc 37. The gases contained in the perforations 38 are extracted by the air jet and are swept into the diluent stream and carried to appropriate analyzers through the port 44, passageways 42 and and tubing 32. The dilution ratio of the device can be adjusted or varied by means of 1) increasing or decreasing the diluent stream flow; (2) varying the volume and/or number of perforations 38; (3) or altering the rotational speed of the perforated disc 37.

The present invention is adapted to be inserted in a duct or stack 21 through an opening such as a three inch opening 19 that is standard for stationary combustion sources or units, and FIG. 1 illustrates the insertion of the device through a'stack or duct wall 21. The total system is characterized by simplicity so that there is no need of a large amount of peripheral hardware and support components.

The inlet or diluent air can be supplied or fed by inexpensive polyethylene tubing 33. The outlet tubing 32 is preferably made of an inert material such as Teflon. The outlet lines need not be heat traced as the moisture content can be reduced by the dilution ratio.

While the present invention has been illustrated and described for use as a device for the source measurement of gases, the configuration of the same can be modified to permit particulate sampling. A possible modification is the addition of an airfoil or baffle near the gas exchange port 44 to enhance or channel the flow of stack gases through the perforations so that in this manner a representative sample of the particulate matter can be captured by the rotating disc. Furthermore, the disc diluter is not limited to use in pollution measurement, and the device may be used in any application requiring a single-step dilution, and the materials of construction can be varied depending upon the diluent and the sample to be diluted.

Other potential applications for the device are those relating to sequential sampling and time-based sampling where the objective is to obtain representative feature does not involve dilutions. These conceptions are found in water-porous oceanographs, marine biology and reaction kinetic studies.

Heretofore the present state of the art involving stack gas sample conditioning and/or dilution has been quite limited, and conventional techniques have usually consisted of extracting a stack gas sample by means of a probe and transmitting the sample to the monitors through heated inert tubing to prevent moisture condensation and loss of sample. In this arrangement the tubing is expensive, cumbersome and requires several amperes of current to maintain the desired temperature. Further, the probe inlet must be filtered and backflushed periodically with compressed air to remove particulate matter entrained on the filter. When the sample reaches the analyzer the moisture present (often l0-12% H O) must be removed before reaching the analyzers detector to avoid erroneous responses or destruction of the measuring device. Moisture removal on a continuous basis requires a refrigerated drying device, and also presents the problem of sample loss through absorption or solution with the water condensate.

The disc diluter of the present invention eliminates the problem of moisture condensation and particulate entrainment by diluting the stack gas sample immediately within the stack environment. Since the moisture and particulate content of the sample are reduced by at least a factor of 1,000, heated sample lines, refrigerated dryers, and particulate filters are eliminated.

The present invention can be readily inserted through any standard three inch sample port such as the port 19 and will require a minimal amount of maintenance. By diluting the measurements, and these monitors have been made commercially available during the past few years and would serve a dual purpose for use by various groups such as private industry and government, i.e. both ambient air and source monitoring with the same analyzer, and this would eliminate the added expense of and duplication of instrumentation and accessories. It will be noted that the materials of construction are readily available, and the device can be easily constructed by the public using the same.

It will now be clear that there is provided a device which accomplishes the objectives heretofore set forth. While the invention has been disclosed in the preferred form, it is to be understood that the specific embodiment thereof as described and illustrated herein is not to be considered in a limited sense as there may be other forms or modifications of the invention which should also be construed to come within the scope of the appended claims.

What is claimed is:

l. A combination fluid sampler and sample dilution device adapted to be placed into a body of fluid to be sampled, comprising:

a. means for entraping and enclosing a sample of the b. means adapted to conduct a continuous flow of sample diluent from a source of diluent to the sampler and thence to a sample analyzer, said diluent conducting means being so constructed that at no time during operation of the sampler is the flow of diluent interrupted,

c. means adapted to bring the entrapped sample into mixing contact with the flowing diluent, whereby the sample is diluted and propelled by the continuously flowing diluent stream to the sample analyzer. 2. The structure as defined in claim 1, wherein the means in (a) comprises:

a. a pair of spaced parallel discs, each of said discs having circumferentially spaced, fluid ingress apertures extending therethrough, the apertures in one disc being substantially in alignment with the apertures in the other disc,

b. an intermediate disc interposed between said spaced discs in surface contact with both of said discs and movable relative thereto, and having at least one aperture extending therethrough and selectively alignable with the apertures in both of said spaced discs by movement of the intermediate disc relative to the spaced discs, and

0. means for moving said intermediate disc relative to the spaced discs to move the aperture in the intermediate disc cyclically into and out of alignment with the apertures in the spaced discs, whereby a sample of said fluid is entrapped in the aperture in the intermediate disc. I

3. The structure is defined in claim 1, wherein the means in (b) includes an adjustable diluent flow rate regulator.

4. The structure as defined in claim 2, wherein the intermediate disc is rotatable.

5. The structure as defined in claim 4 further com prising,

said port by movement of the intermediate disc relative to said spaced discs,

c. a hollow housing attached to the same disc and superposed over said port,

d. said housing having a pair of passageways formed therein and extending from the exterior to the interior thereof, the interior ends of said passageways being in communication with each other at all times,

e. means connecting the exterior end of one of said passageways to said source of diluent and means connecting the exterior end of the other passageway to said analyzer, whereby a sample of fluid entrapped in the aperture in the intermediate disc is diluted by the diluent when the aperture is aligned with said port,

7. A method of sampling and analyzing a fluid comprising:

a. isolating a discrete sample of the fluid from the main body of the fluid,

b. maintaining a constantly flowing stream of sample diluent from a source of said diluent to a fluid ana- .lyzer,

c. mixing said sample with diluent from said constantly flowing stream of diluent thereby diluting the sample, and

d. conveying the diluted sample, along with the diluent stream, to said analyzer, whereby there is maintained a study state flow to the analyzer.

8. A method as defined in claim 7, wherein the extent of dilution of the sample is varied by varying the rate of flow of the diluent.

9. A method as defined in claim 7, wherein the extent of dilution of the sample is varied by varying the period of time during which the diluent stream is in mixing relation with the sample. 

1. A combination fluid sampler and sample dilution device adapted to be placed into a body of fluid to be sampled, comprising: a. means for entraping and enclosing a sample of the fluid, b. means adapted to conduct a continuous flow of sample diluent from a source of diluent to the sampler and thence to a sample analyzer, said diluent conducting means being so constructed that at no time during operation of the sampler is the flow of diluent interrupted, c. means adapted to bring the entrapped sample into mixing contact with the flowing diluent, whereby the sample is diluted and propelled by the continuously flowing diluent stream to the sample analyzer.
 2. The structure as defined in claim 1, wherein the means in (a) comprises: a. a pair of spaced parallel discs, each of said discs having circumferentially spaced, fluid ingress apertures extending therethrough, the apertures in one disc being substantially in alignment with the apertures in the other disc, b. an intermediate disc interposed between said spaced discs in surface contact with both of said discs and movable relative thereto, and having at least one aperture extending therethrough and selectively alignable with the apertures in both of said spaced discs by movement of the intermediate disc relative to the spaced discs, and c. means for moving said intermediate disc relative to the spaced discs to move the aperture in the intermediate disc cyclically into and out of alignment with the apertures in the spaced discs, whereby a sample of said fluid is entrapped in the aperture in the intermediate disc.
 3. The structure is defined in claim 1, wherein the means in (b) includes an adjustable diluent flow rate regulator.
 4. The structure as defined in claim 2, wherein the intermediate disc is rotatable.
 5. The structure as defined in claim 4 further comprising, a. motor means connected to said intermediate disc for rotating the same.
 6. The structure as defined in claim 2, wherein a. one of said pair of spaced discs has a port extending therethrough and located between the apertures in the disc, b. each aperture in the intermediate disc being so located in said disc as to be selectively alignable with said port by movement of the intermediate disc reLative to said spaced discs, c. a hollow housing attached to the same disc and superposed over said port, d. said housing having a pair of passageways formed therein and extending from the exterior to the interior thereof, the interior ends of said passageways being in communication with each other at all times, e. means connecting the exterior end of one of said passageways to said source of diluent and means connecting the exterior end of the other passageway to said analyzer, whereby a sample of fluid entrapped in the aperture in the intermediate disc is diluted by the diluent when the aperture is aligned with said port.
 7. A method of sampling and analyzing a fluid comprising: a. isolating a discrete sample of the fluid from the main body of the fluid, b. maintaining a constantly flowing stream of sample diluent from a source of said diluent to a fluid analyzer, c. mixing said sample with diluent from said constantly flowing stream of diluent thereby diluting the sample, and d. conveying the diluted sample, along with the diluent stream, to said analyzer, whereby there is maintained a study state flow to the analyzer.
 8. A method as defined in claim 7, wherein the extent of dilution of the sample is varied by varying the rate of flow of the diluent.
 9. A method as defined in claim 7, wherein the extent of dilution of the sample is varied by varying the period of time during which the diluent stream is in mixing relation with the sample. 